diff options
Diffstat (limited to 'tvix/eval/src/compiler')
| -rw-r--r-- | tvix/eval/src/compiler/mod.rs | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/tvix/eval/src/compiler/mod.rs b/tvix/eval/src/compiler/mod.rs index 1463bb100eae..941b945a8bb6 100644 --- a/tvix/eval/src/compiler/mod.rs +++ b/tvix/eval/src/compiler/mod.rs @@ -630,16 +630,34 @@ impl Compiler<'_> { self.patch_jump(final_jump); } + /// Compile `assert` expressions using jumping instructions in the VM. + /// + /// ```notrust + /// ┌─────────────────────┐ + /// │ 0 [ conditional ] │ + /// │ 1 JUMP_IF_FALSE →┼─┐ + /// │ 2 [ main body ] │ │ Jump to else body if + /// ┌┼─3─← JUMP │ │ condition is false. + /// Jump over else body ││ 4 OP_ASSERT_FAIL ←┼─┘ + /// if condition is true.└┼─5─→ ... │ + /// └─────────────────────┘ + /// ``` fn compile_assert(&mut self, slot: LocalIdx, node: &ast::Assert) { // Compile the assertion condition to leave its value on the stack. self.compile(slot, &node.condition().unwrap()); self.emit_force(&node.condition().unwrap()); - self.push_op(OpCode::OpAssert, &node.condition().unwrap()); + let then_idx = self.push_op(OpCode::OpJumpIfFalse(JumpOffset(0)), node); - // The runtime will abort evaluation at this point if the - // assertion failed, if not the body simply continues on like - // normal. + self.push_op(OpCode::OpPop, node); self.compile(slot, &node.body().unwrap()); + + let else_idx = self.push_op(OpCode::OpJump(JumpOffset(0)), node); + + self.patch_jump(then_idx); + self.push_op(OpCode::OpPop, node); + self.push_op(OpCode::OpAssertFail, &node.condition().unwrap()); + + self.patch_jump(else_idx); } /// Compile conditional expressions using jumping instructions in the VM. |